Kubota G21E pto spluttering issues

[RobDon]

I have a kubota G21E thats just had new deck belts, pto belts and a full service but now when i engage the pto sometimes it runs up smooth but others its trying to stall and splutter the engine causing vibration. i have since turned the deck and pto pulley over by hand and its all smooth and fairly free, the pto belt tension has been double checked. wondering if this would be a fuel issue when the engine it loaded possibly lift pump? but has ran smoothly sometimes too any help would be appreciated

 

[Cooperhawk]

It takes a lot of torque to engage the deck on these things and I usually throttle down and engage at lower RPMs and then throttle up.

 

[RobDon]

my problem is its very intermittent and would run smooth, since writing this post is and burnt out the stop solenoid and ive tested and its getting 12v all the time when it should only be getting it briefly to shut the engine down